Title:Observational Signatures of a Massive Distant Planet on the Scattering Disk

Abstract: The orbital element distribution of trans-Neptunian objects (TNOs) with large
pericenters has been suggested to be influenced by the presence of an
undetected, large planet at >200 AU from the Sun. To find additional
observables caused by this scenario, we here present the first detailed
emplacement simulation in the presence of a massive ninth planet on the distant
Kuiper Belt. We perform 4 Gyr N-body simulations with the currently known Solar
System planetary architecture, plus a 10 Earth mass planet with similar orbital
parameters to those suggested by Trujillo & Sheppard (2014) or Batygin & Brown
(2016), and 10^5 test particles in an initial planetesimal disk. We find that
including a distant superearth-mass planet produces a substantially different
orbital distribution for the scattering and detached TNOs, raising the
pericenters and inclinations of moderate semimajor axis (50<a<500 AU) objects.
We test whether this signature is detectable via a simulator with the
observational characteristics of four precisely characterized TNO surveys. We
find that the qualitatively very distinct Solar System models that include a
ninth planet are essentially observationally indistinguishable from an outer
Solar System produced solely by the four giant planets. We also find that the
mass of the Kuiper Belt's current scattering and detached populations is
required to be 3-10 times larger in the presence of an additional planet. We do
not find any evidence for clustering of orbital angles in our simulated TNO
population. Wide-field, deep surveys targeting inclined high-pericenter objects
will be required to distinguish between these different scenarios.